Screen for centrifugal machines



June 8, F. HOWEV SCREEN FOR CENTRIFUGL MACHINES Filed Aug. 25, 1941 2Sheets-Sheet 1 `lune 8, 1943. A. F. HowE Y SCREEN FOR CENTRIFUGALMACHINES 2 Sheets-Sheet?l Filed Aug. 25, 1941 Patented June 8, 1943SCREEN FOR CENTRIFUGAL lVIAGHINES Andrew F. Howe, University City, Mo.,assigner to B. H. & M. Company, St. Louis, Mo., a corporation ofMissouri applicati@ August 25, 194.1, serial No. 408,145

12 Claims.

This invention relates to Screens to centrifugal machines; and hasspecial- Vreference to screens of the general type disclosed in mycopending application Serial No. 357,348, filed September 19,

1940, and in my prior Patent No. 2,022,114,Vv No` vember 26, 1935.

An object of the invention is to provide an improved screen of longdurability for use in centrifugal machines comprising a rotary conicalscreen basket made of. durable metal or the like and having numerouslarge discharge openings therethrough, in combination with a screen ofnovel construction and of long durability attached to the inner side ofsaid basket and having numerous outwardly diverging passagestherethrough communicating With said openings through the basket andrelatively of much smaller area than said openings.

Another object of the invention is to provide an improved long lastingscreen for use in centriugal machines comprising an inclined series ofrings arranged one above the other, and means for supporting said ringsin superimposed relationship and providing numerous outwardly divergingpassagesr therethrough or between s aid rings for the discharge ofliquid and smaller particles of waste material from within` the screen'duringVv rotation thereof.

Another object',` ofV the invention is to provide an improved longlasting screen of the character mentioned4 in combination with a conicalbasket enclosing the screen and having numerousrelatively largedischarge openings therethrough, and means for supporting the screen andin rigid relationship with the basket and providing` passages wherebyVthe substances dischargedY through the screen may pass into and` throughsaid openings Ain the basket.

Another object of the invention is to provide an improved screencomposed of a plurality of ringsA of graduated diameters and means forsupporting said rings inf spaced relationship to provide passages forthe discharge of liquid and entrained substances from within the screenduring centrifugal operation of the machine for which the screen isprovided.

Another object of the invention is to provide an improved screencomposed of a coiled band or strip forming a screen device taperingupwardly, and means for attaching together the adjacent coils of said`band or strip in rigid relationship and providing outwardly enlargingpassages for thedischarge of liquids and entrained substances duringoperationV of the screen.

Other objects will appear from the following description, referencebeing made to the annexed drawings, in which- Fig. 1 is a viewpartly inelevation and* partly .in section showing my improved screen and basketattached together in cooperative relationship for operation in acentrifugal machine,`

Fig. 2 is an enlargedA sectional view` showing. more clearly thearrangement` and4 construction of the screen and' its association withthe basket.

Fig. 3 is an enlarged sectional View similar to Fig. z showing a screenof modified construction in which the screen rings are supported inspaced relationship by devices also providing the passages through thescreen.

Fig. 4 is a perspective view'sllowing` a coiled band or strip which maybe usedin forming, the

screen.

Fig. 5` is a detail sectional view showingamodication of theconstruction shownin Fig. 2.56parate spacers being attachedtov theirings..

Fig. 6 is a perspective viewofa portion or. fragment of the spacer showniny Fig. 3.

Fig. 'l is an enlargedplan view. of. a. ring. hav.- ing the spacersintegrally united with the upper side of the lower ring. i

Fig. ,8. is a side elevation or. edge. view of the Fig. 9 is aninverted. plan view of the ring: shown inFigs. ll and2.

Fig. 1l),A is a side elevation or edge View of the same ring inverted.

The present inventionl isv designed and adapted for use in centrifugalseparators or clarifiers-of tegral with the upper end'- of the-basket.`'line-v lower end' ofthe basket I- is formed with an outwardly extendedflange or frame portion. 4 jar'- ranged tobe attached to-*asub-structurewhich', in turn, isv connected.`l with the rotating orydriv'-I ing mechanism in the mannergdisclosecl in my.

said copending application, or otherwise, as dea sired. The metallicbasket I is rotative about a vertical axis and is formed with aconsiderable number of relatively large outlet openings 5. As shown,these openings may be arranged in annular series and spaced apartcircumferentially and vertically.

The screen shown in Figs. l and 2 is composed of a series of rings 6 ofgraduated diameter and circumference complementary tothe inside diameterand inside circumference of the basket I. One of these rings is shown inlower plan View in Fig. 9 and in edge or side elevation in Fig. 10. An-

annular series of spacers 7 is attached to the underside of each ring 6.These spacers extend from the inner edges of said rings to the outeredges thereof in approximately radial directions. The adjacent walls ofthe respective spacers flare or diverge outwardly to provide outwardlyflaring or enlarging passages 8 when said spacers are superimposed uponand attached to the subjacent ring. The inner surfaces or walls 9 of therings 6 and the spacers 'I are smooth, and the walls of all of the ringsare in the same conical plane in order not to interfere with themovement Yin any direction of the liquid and entrained substances towardthe discharge passages 8. Thus, the inner surface ofthe screen,considered in its entirety, is a smooth perforated wall parallel withthe inner surface of the basket I. Also, the rings 6 taper outwardly incross-section, as clearly shown in Fig. 2, so that the passages 8 are ofconsiderably llarger area at their outer or exit ends than at theirinner or inlet ends. Due to the cross-sectional tapered formation of therings 6, the vertical width of the outer ends of the passages 8 isgreatly in excess of the vertical width of the inner or inlet ends ofsaid openings. A large proportion of the passages 8 communicatesdirectly with the openings 5. This arrangement functions to expediterthe discharge of substances through'the openings 5 and to prevent themachine from becoming clogged. The screen rings B'are madeA of hardmetal not easily-abraded or worn, so that they will indefinitely or fora long time resist and endure the abrasive of the liquid and'entrainedsubstances and other solids passing through the machine.

An annular series of upwardly extended ribs I0 is formed integral orrigid with the inner Aside of the basket I, and spaced peripheralportions of the rings 6 are rigidly attached theretol by welding orotherwise. The ribs I0 provide attachments for spaced peripheralportions of the ringsl, and also hold said rings out of contact withtheinnersurface of the basket I, and additionallyprovidevinclined passagesbetween said rings-6 and the basket I to permit unobstructed owfofthecontents discharged from within the Y screen to the discharge openings 5in the basket. i

As shown, a large proportion of the rings 6 extends across the openings5 so that a large numberl of the passages are in direct communicationwith said openings 5 to expedite discharge through said openings 5.

Instead of forming the spacers I on the undersides ofthe ringsV 6, theymay be formed integral or rigid with the upper sides of said rings. Asshownin Figs. 7 and 8, `the spacers l', which are the analogs of thespacers 1, are formed integral with or rigidly attached to the uppersides of the rings 6. These spacers 'I' are attached to the undersidesof the superimposed rings 6 just as the spacers'l are attached to theupper sides of the subjacent rings. Weldings may be utilized as themedium' of attachment in both instances.

A variation of the invention is shown in Fig. 3, the variationconsisting in the means for holding the rings 6 spaced apart. Eachspacer shown in Fig. 3 comprises an annular strip of sheet metaldistorted to form arches II integrally united at their lower ends byconnections I2 which may also be said to consitute inverted arches. Whenthe annular strip of metal is thus distorted, it provides an annularseries of outwardly flaring or enlarging passages I3 for the dischargeof the liquid and entrained lighter solids from within the screen. Theupper surfaces of the arches I I are attached to the undersides of therespective superimposed rings 6 and the lower surfaces of theconnections I2 are attached to the upper sides of the respectivesubjacent rings. Spaced peripheral portions of the rings B and of theannular strips forming the spacers and passages between said rings areattached to the ribs I0, just as spaced portions of the rings 6 in Figs.1 and 2 are attached to the ribs IG. Thus, in this instance, the rings 6and the spacers therefor are held out of direct contact with the innersurface of the basket I so that the liquid and entrained lightersubstances discharged from within the screen may flow freely to andthrough` the openings 5.

Instead of forming the rings 6 separately, the screen may be formed of acontinuous strip I4 coiled; in conical form to provide a conical screengenerally of the shape shown in Fig. 1, or a series of coiled strips maybe used to form the conical screen. Spacers I5 are located betweenadjacent convolutions. These spacers may be similar to the spacers I andattached to the adjacent con? volutions of the coiled strip to provideoutwardly flaring or enlarging passages I6. When thel spacers I5 areattached to the adjacent convolutions throughout the length of the stripor strips forming the screen; a conical screen is pro-l and havingseparate spacer blocks I'I Welded orotherwise attached thereto and beingof the gene eral shape of the spacers 'I and functioning in the `samemanner and for the same purpose. The' showing of the invention-embodiedin a structure comprising a truncated cone is for illustrative purposesonly. It is plain` that the invention may be used in forms other thantruncated cone form. `Other variations may be made Within the scopeofthe invention without departure from the na-Y ture and principlethereof.

I claim:

outward flow of liquid'and` suspended particles;

a metallic frusto-conical screen within said cone l comprising a seriesof rings of graduated diameter and circumference complementary to theinside diameter and inside circumference of said cone, and certain ofwhich rings cross said openings,

within said screen, and ribs integral with the pev,ripheries of saidrings and with the inner sur.- -face of s aid cone holding said screenin rigid.

spaced relationship with respect to said cone.

2. In a device of the character described in -A cluding a metallictruncatedV cone having numer- 75 ous relatively large openingstherethrough for the -1. In a device of the character described in`cluding'a-metallic truncated cone having numer. ous relatively largeopenings therethrough for the outward flow ofliquid and suspendedparticles; a metallic frusto-conical screen within 4said cone comprisinga series of rings of graduateddiameter and circumference complementaryto the inside diameter and inside circumference of said icone andcertain of which rings cross said openings, means rigidly attachingspaced peripheral portions of said rings to said conebetween said open-Voutward flow of liquid and suspended particles; aA

metallic frusto-conical screen vvithin said cone comprising verticallyspaced annular elements .of graduated diameter and circumferencecomplementary to the inside diameter and inside circumference of saidcone and certain of which ringscross saidv openings, spacers betweenand.

holding said elements in vertically spaced relationshipand providingnumerous outwardly opening passages between said rings and communicatingdir ectly with said openings for the, ilow of liquid and suspendedparticles from within said screen, and means integrally attaching spacedportions of the peripheries of said, rings to the inner side of saidcone and providing passages for the flow-of saidliquidrand suspendedparticles to said openings.

4. In a device of the character described including a metallic truncatedcone having numerous relatively large openings therethrough for theoutward flow of liquid and suspended particles; a metallicfrusto-conical screen within said cone comprising a series of rings ofgraduated diameter and circumference complementary to the insidediameter and inside circumference of said cone and certain of whichrings cross said openings, spacer blocks between and holding said ringsin vertically spaced relationship and providing numerious outwardlyopening passages between said rings and communicating directly with saidopenings for the flow of liquid and suspended particles from within saidscreen, said spacer blocks being rigid with the respective rings, andmeans holding said screen integral with and spaced from said cone andproviding passages for the flow of said liquid and suspended particlesto said openings.

5. In a device of the character described including a metallic truncatedcone having numerous relatively large openings therethrough for theoutward flow of liquid and suspended particles; a metallicfrusto-conical screen Within said cone comprising a series of rings ofgraduated diameter and circumference complementary to the insidediameter and inside circumference of said cone, an annular strip ofsheet metal located between each pair of adjacent rings and having bentportions attached to said rings between which it is located andproviding outwardly opening passages between said rings for the now ofliquid and suspended particles from within said screen, and meansholding said screen in rigid connection with said cone and providingpassages for the iiow of said liquid and suspended particles to saidopenings.

6. In a device of the character described including a metallic truncatedcone having nuthe outward flow-of liquidi and suspended particles; afrusto-conical screen within vsaidcon'e comprising a coiled strip'inconicalmform comple'- mentary to the inside diameter` and inside cir-.-

cumference of -said cone, spacers between and attaching together theconvolutions of said strip and holding them in vertically spacedrelationship and providing outwardly opening .passagesbetween saidconvolutions for the flow of liquid andsuspended-particlesfrom withinsaid screen,

and means attaching spaced peripheral portions of said screen to theinner side of said cone and providing passages for the flow of saidliquid andsuspended particles to said openings. l

7. In a device of thechar'acter described-including a substantiallyyinflexible metallic vbasket arranged to rotate about a vertical axis andhav-- ing numerous relatively largeopenings therethrough for theoutflovvl of liquid and suspended particles; a rigid screen within saidbasket having an outside diameter complementary to the inside diameterof said basket and comprising parts of outwardly decreasing taperedthickness in Vertical cross-section arranged in verticallyspacedrelationship and providing passages from the inner periphery to theouter periphery of said screen, the upper and lower walls of said'pas--v sages diver-ging outwardly and forming the outerl vportions ofsaid passages of much greater-ven ticalwidth than their inner portions,certain of said passages communicating directly with saidA openings insaid basket for the ilow'of `liquid andy suspended particles from withinsaid screen, and means located between said openings in`V said basketattaching and holding said screen rigidly within said basket.

8. In a device of the character described including a substantiallyinflexible metallic basket arranged to rotate about a vertical axis andhaving numerous relatively large openings therethrough for the outflowof liquid and suspendedv particles; a rigid screen Within said basketand comprising vertically spaced parts having an outside diametercomplementary to the inside diameter of said basket and of outwardlydecreasing tapered thickness in vertical crosssection, spacers betweenand holding said parts in vertically spaced relationship and formingcircumferentially spaced passages through said screen and having theirouter portions of much greater vertical width than their inner portions,certain of said passages communicating directly with said openings insaid basket for the flow of liquid and suspended particles from withinsaid screen, and means located between said openings in said basketattaching and holding said screen in rigid connection with said basket.

9. In a device of the character described including a metallic truncatedcone having numerous relatively large openings for the outward flow ofliquid and suspended particles; a metallic frusto-conical screen withinsaid cone comprising v a series of rings of graduated diameter andcircumference complementary to the inside diameter and insidecircumference of said cone, said rings tapering outwardly incross-section and having their outer peripheries of relatively much lesscross-sectional thickness than their inner peripheries, spacers betweenand holding said rings in vertically spaced relationship and providingnumerous outwardly opening passages between said rings having theirouter portions of much greater vertical width than their inner portionsand communicating directly with said openmerous relativelyla'rgeopenings therethrough-for:-

ings for the ow of liquid and suspended particles,

from within said screen, and ribs integral with the peripheries of saidrings and with the inner surface of said cone holding said screen inrigid spaced relationship in said cone.

10. In a device of the character described including a metallictruncated cone having numerous relatively large openings for the outwardilow of liquid and suspended particles; a metallic frusto-conical screenwithin said cone comprising a series of rings of graduated diameter andcircumference complementary to the inside diameter and insidecircumference of said cone and tapering outwardly in cross-section andhaving their outer peripheries of relatively much less cross-sectionalthickness than their inner peripheries, means integrally attachingspaced peripheral portions of said rings directly to said cone betweensaid openings, and spacers located between and holding said rings invertically spaced relationship and providing numerous outwardly openingpassages between said rings having their upper and lower walls divergingoutwardly from each other and forming the outer portions of saidpassages of much greater vertical width than their inner portions.

l1. In a device of the character described including a substantiallyinflexible metallic basket arranged to rotate about a vertical axis andhaving numerous relatively large openings therethrough for the outow ofliquid and suspended particles; a screen mounted within said basket andhaving an outside diameter complementary to the inside diameter of saidbasket and having numerous passages opening outwardly from the innerperiphery to the outer periphery of said screen, said passages havingupper and lower:

walls divergingV outwardly from each other 4and `forming the outerportions of said passagesV of.

for the flow of liquid and suspended particles from.

within said screen, and means for holding said screen in rigidconnection withvsaid basket.

12. In a device of the character described including a substantiallyinexible metallic basket arranged to rotate about a vertical axis andhaving numerous relatively large openings therethrough for the outow ofliquid and suspended particles; a screen mounted within said basket andhaving an outside diameter complementary to the inside diameter of saidbasket and having numerous passages opening outwardly from the innerperiphery to the outer periphery of said screen, said passages havingupper and lower walls diverging outwardly from each other and formingthe outer portions of said passages of much greater vertical width thantheir inner portions, certain of said screen passages communicatingdirectly with said openings in said basket for the ow of liquid andsuspended particles from within said screen, and means located betweensaid openings in said-basket attaching spaced peripheral portions ofsaid screen rigidly to said basket and providing passages for the flowof substances from said screen passages to said openings through saidbasket.

ANDREW F. HOWE.

